So just last night everything was completely fine, but today i turned on Krita just to find that UI got bigger, drop toolbars got huge - if I want to open a recent file, the drop list takes the whole screen, all toolbars are noticeably sized up. Also, the UI quality dropped. Even the loading screen artwork is low resolution and all pixelated, the Color wheel is also jagged and uneven. what should I do? It is not to the point that I can't use the program, it's just that it's not what I am used to. I always loved Krita's IU but right now i can't really enjoy it's design.

I already tried to reinstall and played around with window settings - nothing. This just happened overnight.

Okay, so, logically, if something changed, while you did not update Krita, or change Krita's settings, it must be something else on your computer. Uninstalling and reinstalling Krita won't make any difference. It sounds like you changed the resolution for your display, or the scaling factor for your display.

I tried to change the resolution on my display from 125% too 100% which did scaled down the text of UI but not the UI itself. It almost feels like when you scale up a small picture -picture got bigger, but resolution gets worse. I haven't been playing around with my settings on the laptop so I am truly unsure what happened. I'll try to poke around the Krita's settings I guess. Other drawing programs that I have, like Medibang or Jump Paint, do not have this issue - their UI are as they always been.

UPDATE : For those who might have similar problems in the future - everything fixed upon updating Windows. I just randomly updated them and afterwards, Krita is back to normal. I am unsure why this affected only Krita (Medibang and Jump Paint were completely fine), but if your Krita appears low resolution or has a bigger than usual UI - check if there are any updates for your computer.